5 files changed, 117 insertions, 18 deletions
diff --git a/app/models/concerns/issuable.rb b/app/models/concerns/issuable.rb
index 94a0de556f4..852576dbbc2 100644
--- a/app/models/concerns/issuable.rb
+++ b/app/models/concerns/issuable.rb
@@ -25,12 +25,20 @@ module Issuable
   include UpdatedAtFilterable
   include IssuableStates
   include ClosedAtFilterable
+  include VersionedDescription
 
   TITLE_LENGTH_MAX = 255
   TITLE_HTML_LENGTH_MAX = 800
   DESCRIPTION_LENGTH_MAX = 1.megabyte
   DESCRIPTION_HTML_LENGTH_MAX = 5.megabytes
 
+  STATE_ID_MAP = {
+    opened: 1,
+    closed: 2,
+    merged: 3,
+    locked: 4
+  }.with_indifferent_access.freeze
+
   # This object is used to gather issuable meta data for displaying
   # upvotes, downvotes, notes and closing merge requests count for issues and merge requests
   # lists avoiding n+1 queries and improving performance.
@@ -172,13 +180,17 @@ module Issuable
       fuzzy_search(query, [:title])
     end
 
-    # Available state values persisted in state_id column using state machine
+    def available_states
+      @available_states ||= STATE_ID_MAP.slice(*available_state_names)
+    end
+
+    # Available state names used to persist state_id column using state machine
     #
     # Override this on subclasses if different states are needed
     #
-    # Check MergeRequest.available_states for example
-    def available_states
-      @available_states ||= { opened: 1, closed: 2 }.with_indifferent_access
+    # Check MergeRequest.available_states_names for example
+    def available_state_names
+      [:opened, :closed]
     end
 
     # Searches for records with a matching title or description.
@@ -297,6 +309,14 @@ module Issuable
     end
   end
 
+  def state
+    self.class.available_states.key(state_id)
+  end
+
+  def state=(value)
+    self.state_id = self.class.available_states[value]
+  end
+
   def resource_parent
     project
   end
diff --git a/app/models/concerns/issuable_states.rb b/app/models/concerns/issuable_states.rb
index 33bc41d7f44..f0b9f0d1f3a 100644
--- a/app/models/concerns/issuable_states.rb
+++ b/app/models/concerns/issuable_states.rb
@@ -4,22 +4,20 @@ module IssuableStates
   extend ActiveSupport::Concern
 
   # The state:string column is being migrated to state_id:integer column
-  # This is a temporary hook to populate state_id column with new values
-  # and should be removed after the state column is removed.
-  # Check https://gitlab.com/gitlab-org/gitlab-foss/issues/51789 for more information
+  # This is a temporary hook to keep state column in sync until it is removed.
+  # Check https: https://gitlab.com/gitlab-org/gitlab/issues/33814 for more information
+  # The state column can be safely removed after 2019-10-27
   included do
-    before_save :set_state_id
+    before_save :sync_issuable_deprecated_state
   end
 
-  def set_state_id
-    return if state.nil? || state.empty?
+  def sync_issuable_deprecated_state
+    return if self.is_a?(Epic)
+    return unless respond_to?(:state)
+    return if state_id.nil?
 
-    # Needed to prevent breaking some migration specs that
-    # rollback database to a point where state_id does not exist.
-    # We can use this guard clause for now since this file will
-    # be removed in the next release.
-    return unless self.has_attribute?(:state_id)
+    deprecated_state = self.class.available_states.key(state_id)
 
-    self.state_id = self.class.available_states[state]
+    self.write_attribute(:state, deprecated_state)
   end
 end
diff --git a/app/models/concerns/milestoneish.rb b/app/models/concerns/milestoneish.rb
index 3deb86da6cf..42b370990ac 100644
--- a/app/models/concerns/milestoneish.rb
+++ b/app/models/concerns/milestoneish.rb
@@ -6,7 +6,9 @@ module Milestoneish
   end
 
   def closed_issues_count(user)
-    count_issues_by_state(user)['closed'].to_i
+    closed_state_id = Issue.available_states[:closed]
+
+    count_issues_by_state(user)[closed_state_id].to_i
   end
 
   def complete?(user)
@@ -117,7 +119,7 @@ module Milestoneish
 
   def count_issues_by_state(user)
     memoize_per_user(user, :count_issues_by_state) do
-      issues_visible_to_user(user).reorder(nil).group(:state).count
+      issues_visible_to_user(user).reorder(nil).group(:state_id).count
     end
   end
 
diff --git a/app/models/concerns/versioned_description.rb b/app/models/concerns/versioned_description.rb
new file mode 100644
index 00000000000..63a24aadc8a
--- /dev/null
+++ b/app/models/concerns/versioned_description.rb
@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module VersionedDescription
+  extend ActiveSupport::Concern
+
+  included do
+    attr_accessor :saved_description_version
+
+    has_many :description_versions
+
+    after_update :save_description_version
+  end
+
+  private
+
+  def save_description_version
+    self.saved_description_version = nil
+
+    return unless Feature.enabled?(:save_description_versions, issuing_parent)
+    return unless saved_change_to_description?
+
+    unless description_versions.exists?
+      description_versions.create!(
+        description: description_before_last_save,
+        created_at: created_at
+      )
+    end
+
+    self.saved_description_version = description_versions.create!(description: description)
+  end
+end
diff --git a/app/models/concerns/worker_attributes.rb b/app/models/concerns/worker_attributes.rb
new file mode 100644
index 00000000000..af40e9e3b19
--- /dev/null
+++ b/app/models/concerns/worker_attributes.rb
@@ -0,0 +1,48 @@
+# frozen_string_literal: true
+
+module WorkerAttributes
+  extend ActiveSupport::Concern
+
+  class_methods do
+    def feature_category(value)
+      raise "Invalid category. Use `feature_category_not_owned!` to mark a worker as not owned" if value == :not_owned
+
+      worker_attributes[:feature_category] = value
+    end
+
+    # Special case: mark this work as not associated with a feature category
+    # this should be used for cross-cutting concerns, such as mailer workers.
+    def feature_category_not_owned!
+      worker_attributes[:feature_category] = :not_owned
+    end
+
+    def get_feature_category
+      get_worker_attribute(:feature_category)
+    end
+
+    def feature_category_not_owned?
+      get_worker_attribute(:feature_category) == :not_owned
+    end
+
+    protected
+
+    # Returns a worker attribute declared on this class or its parent class.
+    # This approach allows declared attributes to be inherited by
+    # child classes.
+    def get_worker_attribute(name)
+      worker_attributes[name] || superclass_worker_attributes(name)
+    end
+
+    private
+
+    def worker_attributes
+      @attributes ||= {}
+    end
+
+    def superclass_worker_attributes(name)
+      return unless superclass.include? WorkerAttributes
+
+      superclass.get_worker_attribute(name)
+    end
+  end
+end